[PATCH] D40440: [TailRecursionElimination] Skip debug intrinsics.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
Herald added a subscriber: JDevlieghere.

I think we do not need to analyze debug intrinsics here, as they should
not impact codegen. This has 2 benefits: 1) slightly less work to do and

2. avoiding generating optimization remarks for converting calls to

debug intrinsics to tail calls, which are not really helpful for users.

Based on work by Sander de Smalen.


https://reviews.llvm.org/D40440

Files:
  lib/Transforms/Scalar/TailRecursionElimination.cpp
  test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll


Index: test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll
===================================================================
--- test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll
+++ test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll
@@ -96,8 +96,8 @@
 
 ; OPTIMIZATION_LEVEL_2: define i32 @maxB(i32 %x, i32 %y)
 ; OPTIMIZATION_LEVEL_2-NEXT: entry:
-; OPTIMIZATION_LEVEL_2-NEXT: tail call void @llvm.dbg.value(metadata i32 %x, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
-; OPTIMIZATION_LEVEL_2-NEXT: tail call void @llvm.dbg.value(metadata i32 %y, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
+; OPTIMIZATION_LEVEL_2-NEXT: call void @llvm.dbg.value(metadata i32 %x, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
+; OPTIMIZATION_LEVEL_2-NEXT: call void @llvm.dbg.value(metadata i32 %y, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
 ; OPTIMIZATION_LEVEL_2-NEXT: %0 = tail call i32 @maxA(i32 %x, i32 %y) #{{[0-9]+}}, !dbg !{{[0-9]+}}
 ; OPTIMIZATION_LEVEL_2-NEXT: ret i32 %0, !dbg !{{[0-9]+}}
 ; OPTIMIZATION_LEVEL_2-NEXT: }
Index: lib/Transforms/Scalar/TailRecursionElimination.cpp
===================================================================
--- lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -230,7 +230,7 @@
         Escaped = ESCAPED;
 
       CallInst *CI = dyn_cast<CallInst>(&I);
-      if (!CI || CI->isTailCall())
+      if (!CI || CI->isTailCall() || isa<DbgInfoIntrinsic>(&I))
         continue;
 
       bool IsNoTail = CI->isNoTailCall() || CI->hasOperandBundles();


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